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United States Patent 9 Claims. or. 260310) It is already known thatfluorescent 1,3-diarylor 1,3,5- triaryl-n -pyrazoline compounds can besuccessfully used for the optical brightening of fiber materials, filmsand the like. Generally, these A -pyrazoline compounds possess inaddition to various other substituents at least one negative substituentin the phenyl radical bound to the nitrogen atom.

Now we were surprised to find that as optical brighteners there can beused more successfully the 1,3-diaryl- A -pyrazoline compoundscorresponding to the general formula H CH2 N S O 2-X (I) in which Rrepresents an aryl radical which may be substituted, more particularly aphenyl radical, and X stands for the group -'CH CH -OH, CH=CH andespecially for the group -CH -CH SO Me, Me representing a cation. Thegroup has the advantage of imparting to the compounds a permanentsolubility in water. It is suitable, however, to use as cation Me suchions which likewise promote the solubility in water. There arepreferably used the ions of the alkali metals such as sodium orpotassium and the ammonium ion. The substituents of the radical R shallbe of such a condition that they do not change too much the absorptionand emission maxi-ma of the unsubstituted compound. As substituentshalogen atoms, preferably chlorine or bromine, and also low molecularweight alkyl radicals such as methyl, ethyl, isopropyl or butyl, that isto say those which contain up to 4 or 5 carbon atoms are particularlysuitable. The said substituents may be present several times in thephenyl nucleus, for example chlorine atoms in position 3 and 4. Thesecompounds are distinguished by an excellent power of fluorescence whenbrightening fiber material, especially of polyarnide, wool skin hairs(furs) and acetylated cellulose.

The A -pyrazolines of the general Formula I used as brighteners in thepresent invention can be prepared in various manner, for example byreacting B-halogeno-alkylaryl ketones withhydrazinophenyl-fi-hydroxyethylsulfones orhydrazinophenyl-B-sulfoethylsulfones. The A pyrazolines (Formula I: X=CHCH OH) obtained with the hydrazinophenyl-B-hydroxyethylsulfones can beconverted by reesterification with concentrated sulfuric acid into theirsulfuric acid esters which then can be isolated in the form of theiralkali metal salts.

The thus obtained neutral sulfuric acid esters (Formula I: X=CH CH OSOMe) can be converted in an aqueous solution, if desired during thedyeing process, by the action of alkaline agents, into the very reactivevinylsulfonyl compounds (Formula I:

which in known manner are capable of adding hydrogen active compounds(for example alcohols, amines, mercaptanes) When agents having analkaline action are allowed to act on the said sulfuric acid esters inthe presence of salts of the sulfurous acid, for example sodium sulfiteand, occasionally at an elevated temperature, there are obtained also inthis way the salts of the ,B-sulfoethylsulfonyl compounds (Formula I:

As ,B-halogenoalkylaryl ketones there are mentioned:,B-chloroethylphenyl ketone, fi-chloroethyl-p-chlorophenyl ketone,p-chloroethyl-m, p-dichlorophenyl ketone, 8-chloroethyl-p-bromophenylketone, fl-chloroethyl-pmethylphenyl ketone andB-chloroethyl-p-methoxyphenyl ketone. As hydrazinophenyl-B-hydroxyor-B-sulfoethylsulfones there may be used the4-hydrazinophenylfi-hydroxy-ethylsulfone or the 4-hydrazinophenyl-B-sulfoethylsulfone.

The proposed brighteners may be used in the usual manner. As far as thebrighteners are soluble in water, they are suitably used in the form ofan aqueous solution and as far as they are insoluble in water, they maybe used in the form of aqueous dispersions, in a given case, with thehelp of dispersing agents. The amounts required for the brightening testvary within wide limits and can easily be determined by preliminarytests.

It is of particular advantage that the new brighteners can be used inthe most different bleaching baths so that an additional Working step isdropped. In combination with the usual detergents, the proposedbrighteners yield also white effects. The compounds can be further usedfor shading white and coloured soaps.

Another field of application of these substances is their use in dyeingbaths whereby there are obtained bright, brilliant dyeings which areparticularly desired with pastel tints.

It is also easily possible to employ the said compounds in the mostdifferent finishing processes for example when sizing and softening. Itis to be stressed that part of these substances can be used in the highquality finishing with some condensable resins without losing theirbrightening elfect.

The following examples serve to illustrate the invention but they arenot intended to limit it thereto, the parts being by Weight unlessotherwise stated.

Example 1 A polycaprolactam fabric was treated for 20 minutes at 60 C.with a solution containing 1% formic acid of strength and 0.4% of thecompound of the following constitution (II) l soicmomso Na (II) Thefabric showed an excellent degree of white tint which could not bereached without the use of an optical brightener.

The determination of the degree of white effected with a Zeiss Elrephoapparatus gave a value of 81%, compared to magnesium oxide as thestandard at a wave length of 460 m (unbrightened fabric: 71%).

The compound of the Formula II cited above was prepared in the followingmanner:

43.2 parts of 4-hydrazinophenyl-p-hydroxyethylsulfone and 40.8 parts offi-chloroethyl-p-chlorophenyl ketone were refluxed for 1 hour in 400parts of volume of methanol to which 40 parts by volume of pyridine wereadded. The reaction mixture was then cooled to a temperature within therange of C. and C., the temperature was maintained for 2 hours and thecrystallized 1-(4-hydroxyethylsulfonyl-phenyl) 3-(4"-chlorophenyl)-Apyrazoline VII having a melting point of 222 C. was separated bysuction-filtration. For reesterification, 25 parts of the dry A-pyrazoline VII were introduced at room temperature into 150 parts ofconcentrated sulfuric acid and the whole was stirred for 15 hours. Thesolution was then poured onto 750 parts by volume of ice water, stirredfor 1 hour in the cold, the precipitated acid, sulfuric acid ester wasseparated by suction-filtration and milled for several hours with asaturated methanolic potassium acetate solution in a ball mill. Thepotassium salt of the sulfuric acid ester was separated bysuction-filtration, washed with ice water until it was free from sulfateions and then dried at 60 C. under reduced pressure.

For preparing Compound II, 24.2 parts of the potassium salt of thesulfuric acid ester were boiled for 150 minutes under reflux in 350parts of volume of water with 25.2 parts of crystallized sodium sulfiteuntil a specimen after addition of dilute sodium hydroxide solution didno longer show a precipitation. Little impurities were then separated bysuction-filtration, the clear solution was mixed with 37.5 parts ofsodium chloride and the Compound II was isolated after cooling of thesolution. The product was then washed with a sodium chloride solution ofstrength until it was free from sulfate ions and dried at 60 C. underreduced pressure.

Example 2 Into a liquid mild detergent of the following composition:

Percent Alkylarylsulfonate 10 Sodium salt of oleylmethyltauride 4Para-toluenesulfonate 6 Potassium pyrophosphate 12 Water 67.7

0.3% of the optical brightener having the following composition (III)CE: /N N S OzCI'IZCI'IZSOBNfi (III) was incorporated.

Knitted fabrics of polycaprolactam showed already after a singletreatment for minutes at 50 C. and a goods-to-liquor ratio of 1:30 with5 grams of the above deter-gent per liter of bath a brilliantbrightening. Even after several washes, the material showed no signs ofbrightener accumulations.

4 The compound was also very active when brightening fur hairs. Thecompound of Formula II was prepared in the manner described in Example 1with the use of ,B-chloroethylphenyl ketone.

Example 3 A woolen flannel was bleached for 3 hours at C. with asolution containing Percent Hydrogen peroxide of 35% strength 40 Sodiumpyrophosphate 4 Ammonia of 25 %strength 2 After acidification with 2% ofacetic acid of 100% strength for 15 minutes in the cold, the materialwas bleached for minutes at 50 C. in a reducing solution containing perliter.

4% sodium dithionite and 0.4% compound of Formula II,

and then acidified again.

The woolen fabric thus treated showed a brilliant white. The degree ofwhite tint was improved from 69% (unbri-ghtened fabric) to 78%.

Example 4 Example 5 A bleached woolen yarn was dyed with a solutioncontaining 0.1% of the dyestuff of the formula Cll;

SOsNa 2% of acetic acid of strength 5% of Glaubers salt 5% of ammoniumacetate and 1% of Compound (IV) of the formula SO20 H1O HzOSQgNa. (W)

This treatment yielded a very bright tint which could not be reachedwithout the use of optical brighteners.

The Compound IV was prepared in the manner de scribed in Example 1 withthe use of p-chloroethylphenyl ketone and neutralisation of the sulfuricacid ester with sodium bicarbonate.

Example 6 For obtaining a high quality finishing, a bleachedpolycaprolactam talfeta was impregnated with adimethyloldihydroxy-ethylene urea and magnesium chloride as catalyst.1.5 grams of Compound (V) of the formula E tQ | SOzCHzCHzOSOaK Example 7For obtaining a smooth, soft handle, a knitted fabric of polycaprolactamwas treated for 20 minutes at 60 C. in a winch vat with a solutioncontaining 2% of a mixture of fatty acid sarcosides, 0.4% (calculated onthe weight of the goods) of an aqueous dispersion of the followingCompound (VI) WeQ CH 1% S'OzCI-I=CII (VI) having been added to the bath.

The degree of white was thereby improved from 71.3% (crude fabric) to80.9% and a pleasant, smooth handle was obtained.

For preparing the vinylsulfonyl Compound (VI), 9.7 parts of thepotassium salt of the sulfuric acid ester indicated in Example 1 weredissolved at 80 C. in 200 parts by volume of water, the solution wasallowed to cool down to 20 C. and then rendered alkaline to triazenepaper (pH about -11) by dropwise adding about 25 parts by volume of a 2N-sodium hydroxide solution. The solution was then stirred for 60minutes at C., the precipitated vinylsulfonyl compound was separated bysuction-filtration, washed with water until neutrality was reached anddried at 60 C. under reduced pressure. After a single recrystallisationfrom butanol, the vinylsulfonyl Compound (VI) possessed a melting pointof 192 C.

Example 8 An untreated knitted fabric of polycaprolactam was bleachedfor 60 minutes at a temperature within the range of 80 C. and 85 C., ata goods-to-liquor ratio of 1:20, in a bath containing per liter 0.5 gramsodium chlorite of 100% strength, 0.2 cc. acetic acid of 100% strengthand 0.2 gram of an aqueous dispersion of the following Compound (VII) 0H, lq \N S OzCHzOHQOH (VII) This bath was adjusted to pH 3.5 withconcentrated sulfuric acid. After this treatment, the material exhibiteda brilliant bluish white which could not be reached without the use ofan optical brightener. The compound (VII) was prepared as described inExample 1.

Example 9 A woolen flannel was bleached for minutes at a temperaturewithin the range of 45 C. and 50 C. with an aqueous dispersioncontaining 30% hydrogen peroxide of 35% strength 3% sodium pyrophosphate2% ammonia of 25% strength and 0.4% of the compound of Formula VIII ISOzC HzC H2011 (VIII) and then rinsed hot and cold.

The fabric thus treated showed a pure white and a brilliant brightening.

Compound (VIII) was prepared in the manner described in Example 1 withthe use of the fl-chloroethylphenyl ketone.

Example 10 Chrome-tanned lambskins were treated for 30 minutes at 35 C.in the winch vat, at a goods-to-liquor ratio of 1:30, calculated on theweight of the dry skins, in a bath containing per liter 1 gram of aproduct obtained by the reaction of 1 mole of nonylphenol ortributylphenol with about 14-16 moles of ethylene oxide. The materialwas then moved for 30-60 minutes at 50 C. in the winch vat in a freshbath containing per liter 4 grams of sodium dithionite (Na S O and0.050.5 gram of the optical brightener of the Formula III. The materialwas then rinsed in a fresh bath, centrifuged and the skins were thensubjected to the usual finishing operation.

What we claim is:

1. 1,3-diaryl-A -pyrazoline of the formula SOZX in which R representsphenyl, halophenyl or lower alkyl phenyl, X stands for CH=CH or CH CH SOMe, and Me represents sodium, potassium or ammonium.

7 8 2. 1,3-diaryl-A -pyrazo1ine of the formula 7. The compound of theformula OHzOR Q l H CHzC CH2 N I II CH1 N in which R stands for a phenylradical, and Me represents sodium, potassium or ammonium. S. Thecompound of the formula 3. Compound of the formula I SOzC 11 CIIQOSOsNB,

H CH2 N CH N N f I B 0 C11 on oso K SO2-CH CII SO3Na 2 2 2 3 4. Compoundof the formula 9. The compound of the formula i 0 H2 fi CH2 N on N N lSO2CH2CH2SO3K slorcnzcm 5. Compound of the formula References Cited bythe Examiner OH,-CC1 (IJHZ Q UNITED STATES PATENTS 2,610,969 9/1952Kendall et al. 260-310 2,702,759 2/1955 Scalera et a1. ll733.5 2,873,2062/1959 Geigy et al. 117-33.5 2,897,206 7/1959 Fukui et al. 2603l02,976,295 3/1961 Plue 26031O I 2,985,593 5/1961 Broderick et a1. 2260-310 SOzClIn-OH2SO3N8 3,013,015 12/1961 Plue 2603l0 6 compound of thef la 3,133,080 5/1964 Sarkar et al. 260310 FOREIGN PATENTS F 41 4 0 62 31,30 ,61 8/19 France.

f 5 JOHN D. RANDOLPH, Acting Primary Examiner.

NICHOLAS S. RIZZO, WALTER A. MODANCE,

Examiners.

NATALIE TROUSOF, Assistant Examiner. s'oz-oHr-omsouz

1. 1,3-DIARYL-$2-PYRAZOLINE OF THE FORMULA